feat: feature:detail - complete MVI detail screen with Stitch design …

app/build.gradle.kts

@@ -6,6 +6,7 @@ plugins {
     alias(libs.plugins.hilt)
     alias(libs.plugins.ksp)
     alias(libs.plugins.detekt)
+    alias(libs.plugins.kotlin.serialization)
     jacoco
 }
 
@@ -134,8 +135,10 @@ dependencies {
     implementation(project(":data:product"))
     implementation(project(":core:designsystem"))
     implementation(project(":feature:catalog"))
+    implementation(project(":feature:detail"))
     implementation(libs.androidx.navigation.compose)
     implementation(libs.hilt.navigation.compose)
+    implementation(libs.kotlinx.serialization.json)
     testImplementation(libs.junit)
     androidTestImplementation(libs.androidx.junit)
     androidTestImplementation(libs.androidx.espresso.core)
@@ -170,7 +173,8 @@ tasks.register<JacocoReport>("jacocoTestReport") {
         ":domain:product:test",
         ":core:common:test",
         ":data:product:testDebugUnitTest",
-        ":feature:catalog:testDebugUnitTest"
+        ":feature:catalog:testDebugUnitTest",
+        ":feature:detail:testDebugUnitTest"
     )
 
     reports {
@@ -228,17 +232,32 @@ tasks.register<JacocoReport>("jacocoTestReport") {
         exclude(fileFilter)
     }
 
+    val detailTree = fileTree(project(":feature:detail").layout.buildDirectory.get()) {
+        include("intermediates/built_in_kotlinc/debug/compileDebugKotlin/classes/**/*.class")
+        exclude(fileFilter)
+    }
+
     sourceDirectories.setFrom(
         files(
             "src/main/java",
             "${project(":domain:product").projectDir}/src/main/java",
             "${project(":core:common").projectDir}/src/main/java",
             "${project(":data:product").projectDir}/src/main/java",
-            "${project(":feature:catalog").projectDir}/src/main/java"
+            "${project(":feature:catalog").projectDir}/src/main/java",
+            "${project(":feature:detail").projectDir}/src/main/java"
         )
     )
 
-    classDirectories.setFrom(files(appTree, domainTree, coreCommonTree, dataTree, catalogTree))
+    classDirectories.setFrom(
+        files(
+            appTree,
+            domainTree,
+            coreCommonTree,
+            dataTree,
+            catalogTree,
+            detailTree
+        )
+    )
 
     executionData.setFrom(
         files(
@@ -256,6 +275,9 @@ tasks.register<JacocoReport>("jacocoTestReport") {
             },
             fileTree(project(":feature:catalog").layout.buildDirectory.get()) {
                 include("jacoco/testDebugUnitTest.exec")
+            },
+            fileTree(project(":feature:detail").layout.buildDirectory.get()) {
+                include("jacoco/testDebugUnitTest.exec")
             }
         )
     )
@@ -307,6 +329,14 @@ tasks.register<JacocoCoverageVerification>("jacocoTestCoverageVerification") {
                 minimum = "0.75".toBigDecimal()
             }
         }
+
+        rule {
+            element = "CLASS"
+            includes = listOf("com.example.catalogapp.feature.detail.*ViewModel*")
+            limit {
+                minimum = "0.75".toBigDecimal()
+            }
+        }
     }
 
     val fileFilter = listOf(
@@ -360,17 +390,32 @@ tasks.register<JacocoCoverageVerification>("jacocoTestCoverageVerification") {
         exclude(fileFilter)
     }
 
+    val detailTree = fileTree(project(":feature:detail").layout.buildDirectory.get()) {
+        include("intermediates/built_in_kotlinc/debug/compileDebugKotlin/classes/**/*.class")
+        exclude(fileFilter)
+    }
+
     sourceDirectories.setFrom(
         files(
             "src/main/java",
             "${project(":domain:product").projectDir}/src/main/java",
             "${project(":core:common").projectDir}/src/main/java",
             "${project(":data:product").projectDir}/src/main/java",
-            "${project(":feature:catalog").projectDir}/src/main/java"
+            "${project(":feature:catalog").projectDir}/src/main/java",
+            "${project(":feature:detail").projectDir}/src/main/java"
         )
     )
 
-    classDirectories.setFrom(files(appTree, domainTree, coreCommonTree, dataTree, catalogTree))
+    classDirectories.setFrom(
+        files(
+            appTree,
+            domainTree,
+            coreCommonTree,
+            dataTree,
+            catalogTree,
+            detailTree
+        )
+    )
 
     executionData.setFrom(
         files(
@@ -388,6 +433,9 @@ tasks.register<JacocoCoverageVerification>("jacocoTestCoverageVerification") {
             },
             fileTree(project(":feature:catalog").layout.buildDirectory.get()) {
                 include("jacoco/testDebugUnitTest.exec")
+            },
+            fileTree(project(":feature:detail").layout.buildDirectory.get()) {
+                include("jacoco/testDebugUnitTest.exec")
             }
         )
     )

app/src/main/java/com/example/catalogapp/navigation/CatalogNavHost.kt

@@ -5,27 +5,34 @@ import androidx.navigation.NavHostController
 import androidx.navigation.compose.NavHost
 import androidx.navigation.compose.composable
 import androidx.navigation.compose.rememberNavController
+import androidx.navigation.toRoute
 import com.example.catalogapp.feature.catalog.CatalogScreen
+import com.example.catalogapp.feature.detail.DetailScreen
 
 @Composable
 fun CatalogNavHost(
     navController: NavHostController = rememberNavController()
 ) {
     NavHost(
         navController = navController,
-        startDestination = Screen.Catalog.route
+        startDestination = CatalogRoute
     ) {
-        composable(Screen.Catalog.route) {
+        composable<CatalogRoute> {
             CatalogScreen(
                 onNavigateToDetail = { productId ->
-                    navController.navigate(Screen.Detail.createRoute(productId))
+                    navController.navigate(DetailRoute(productId))
                 }
             )
         }
 
-        // Detail screen — added in next session
-        composable(Screen.Detail.route) {
-            // Placeholder until feature:detail is built
+        composable<DetailRoute> { backStackEntry ->
+            val route = backStackEntry.toRoute<DetailRoute>()
+            DetailScreen(
+                productId = route.productId,
+                onNavigateBack = { navController.popBackStack() }
+            )
         }
     }
 }
+
+

app/src/main/java/com/example/catalogapp/navigation/Routes.kt

@@ -0,0 +1,14 @@
+package com.example.catalogapp.navigation
+
+import kotlinx.serialization.Serializable
+
+// ─── Type-safe route definitions ──────────────────────────────────────────────
+// Each route is a @Serializable class/object — Navigation generates
+// the route string automatically, no manual string formatting needed.
+// Compile-time safety: wrong argument types fail at build time, not runtime.
+
+@Serializable
+object CatalogRoute
+
+@Serializable
+data class DetailRoute(val productId: Int)

build.gradle.kts

@@ -8,4 +8,5 @@ plugins {
     alias(libs.plugins.hilt) apply false
     alias(libs.plugins.ksp) apply false
     alias(libs.plugins.detekt) apply false
+    alias(libs.plugins.kotlin.serialization) apply false
 }

feature/detail/.gitignore

@@ -0,0 +1 @@
+/build

feature/detail/build.gradle.kts

@@ -0,0 +1,61 @@
+plugins {
+    alias(libs.plugins.android.library)
+    alias(libs.plugins.kotlin.compose)
+    alias(libs.plugins.hilt)
+    alias(libs.plugins.ksp)
+    alias(libs.plugins.detekt)
+    jacoco
+}
+
+android {
+    namespace = "com.example.catalogapp.feature.detail"
+    compileSdk = 36
+
+    defaultConfig {
+        minSdk = 24
+    }
+
+    compileOptions {
+        sourceCompatibility = JavaVersion.VERSION_17
+        targetCompatibility = JavaVersion.VERSION_17
+    }
+
+    buildFeatures {
+        compose = true
+    }
+}
+
+jacoco {
+    toolVersion = "0.8.12"
+}
+
+detekt {
+    config.setFrom(files("$rootDir/config/detekt/detekt.yml"))
+    buildUponDefaultConfig = true
+    source.setFrom("src/main/java")
+}
+
+dependencies {
+    implementation(project(":domain:product"))
+    implementation(project(":core:common"))
+    implementation(project(":core:designsystem"))
+
+    implementation(platform(libs.androidx.compose.bom))
+    implementation(libs.androidx.compose.ui)
+    implementation(libs.androidx.compose.material3)
+    implementation(libs.androidx.compose.ui.tooling.preview)
+    implementation(libs.androidx.compose.foundation)
+    implementation(libs.androidx.compose.material.icons.extended)
+    debugImplementation(libs.androidx.compose.ui.tooling)
+
+    implementation(libs.androidx.lifecycle.runtime.ktx)
+    implementation(libs.hilt.android)
+    ksp(libs.hilt.compiler)
+    implementation(libs.hilt.navigation.compose)
+    implementation(libs.kotlinx.coroutines.android)
+    implementation(libs.coil.compose)
+
+    testImplementation(libs.junit)
+    testImplementation(libs.mockk)
+    testImplementation(libs.kotlinx.coroutines.test)
+}

feature/detail/proguard-rules.pro

@@ -0,0 +1,21 @@
+# Add project specific ProGuard rules here.
+# You can control the set of applied configuration files using the
+# proguardFiles setting in build.gradle.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}
+
+# Uncomment this to preserve the line number information for
+# debugging stack traces.
+#-keepattributes SourceFile,LineNumberTable
+
+# If you keep the line number information, uncomment this to
+# hide the original source file name.
+#-renamesourcefileattribute SourceFile

feature/detail/src/androidTest/java/com/example/catalogapp/feature/detail/ExampleInstrumentedTest.kt

@@ -0,0 +1,24 @@
+package com.example.catalogapp.feature.detail
+
+import androidx.test.platform.app.InstrumentationRegistry
+import androidx.test.ext.junit.runners.AndroidJUnit4
+
+import org.junit.Test
+import org.junit.runner.RunWith
+
+import org.junit.Assert.*
+
+/**
+ * Instrumented test, which will execute on an Android device.
+ *
+ * See [testing documentation](http://d.android.com/tools/testing).
+ */
+@RunWith(AndroidJUnit4::class)
+class ExampleInstrumentedTest {
+    @Test
+    fun useAppContext() {
+        // Context of the app under test.
+        val appContext = InstrumentationRegistry.getInstrumentation().targetContext
+        assertEquals("com.example.catalogapp.feature.detail.test", appContext.packageName)
+    }
+}

feature/detail/src/main/AndroidManifest.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+
+</manifest>

feature/detail/src/main/java/com/example/catalogapp/feature/detail/DetailContract.kt

@@ -0,0 +1,33 @@
+package com.example.catalogapp.feature.detail
+
+import com.example.catalogapp.domain.product.Product
+
+// ─── UI State ─────────────────────────────────────────────────────────────────
+data class DetailUiState(
+    val product: Product? = null,
+    val isLoading: Boolean = false,
+    val error: String? = null,
+    val isWishlisted: Boolean = false,
+    val isDescriptionExpanded: Boolean = false
+) {
+    val showLoading: Boolean get() = isLoading && product == null
+    val showError: Boolean get() = error != null && !isLoading && product == null
+    val showContent: Boolean get() = product != null
+}
+
+// ─── Intent ───────────────────────────────────────────────────────────────────
+sealed class DetailIntent {
+    data class LoadProduct(val productId: Int) : DetailIntent()
+    object NavigateBack : DetailIntent()
+    object ToggleWishlist : DetailIntent()
+    object AddToCart : DetailIntent()
+    object ToggleDescription : DetailIntent()
+    object ShareProduct : DetailIntent()
+}
+
+// ─── Effect ───────────────────────────────────────────────────────────────────
+sealed class DetailEffect {
+    object NavigateBack : DetailEffect()
+    data class ShowSnackbar(val message: String) : DetailEffect()
+    data class ShareProduct(val title: String, val price: Double) : DetailEffect()
+}